1. Field of the Invention
The present invention relates to a cable winding apparatus and method and is useful in particular, but not exclusively, for winding the power cables of electrically driven mobile cranes.
2. Description of Related Art
A typical power cable which is required to be wound on a reel on a mobile crane may have a diameter of 21/2 inches and a length of 3000 ft. If such a cable is wound on a monospiral reel, because of the above dimensions of the cable, the monospiral reel requires a diameter of 30 ft.
Such a large reel involves an undesirably high capital cost and is vulnerable to damage. Also, it is difficult to install and subjects the cable to undesirable high tensions and wear and, moreover, is heavy and presents a large wind exposure area. A further disadvantage of a cable reel of this size is that it has a high inertia and, consequently, can easily exert an unacceptably high tension on the cable.
The alternative of a level wind drum has the disadvantages that the cable is not ventilated at all sides and may therefore be derated; that the cable is unduly tension; and that a large floor area is required to accommodate the level wind reel.